xref: /linux/drivers/input/serio/gscps2.c (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a) 
1 /*
2  * drivers/input/serio/gscps2.c
3  *
4  * Copyright (c) 2004-2006 Helge Deller <deller@gmx.de>
5  * Copyright (c) 2002 Laurent Canet <canetl@esiee.fr>
6  * Copyright (c) 2002 Thibaut Varene <varenet@parisc-linux.org>
7  *
8  * Pieces of code based on linux-2.4's hp_mouse.c & hp_keyb.c
9  *	Copyright (c) 1999 Alex deVries <alex@onefishtwo.ca>
10  *	Copyright (c) 1999-2000 Philipp Rumpf <prumpf@tux.org>
11  *	Copyright (c) 2000 Xavier Debacker <debackex@esiee.fr>
12  *	Copyright (c) 2000-2001 Thomas Marteau <marteaut@esiee.fr>
13  *
14  * HP GSC PS/2 port driver, found in PA/RISC Workstations
15  *
16  * This file is subject to the terms and conditions of the GNU General Public
17  * License.  See the file "COPYING" in the main directory of this archive
18  * for more details.
19  *
20  * TODO:
21  * - Dino testing (did HP ever shipped a machine on which this port
22  *                 was usable/enabled ?)
23  */
24 
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/serio.h>
29 #include <linux/input.h>
30 #include <linux/interrupt.h>
31 #include <linux/spinlock.h>
32 #include <linux/delay.h>
33 #include <linux/ioport.h>
34 
35 #include <asm/irq.h>
36 #include <asm/io.h>
37 #include <asm/parisc-device.h>
38 
39 MODULE_AUTHOR("Laurent Canet <canetl@esiee.fr>, Thibaut Varene <varenet@parisc-linux.org>, Helge Deller <deller@gmx.de>");
40 MODULE_DESCRIPTION("HP GSC PS2 port driver");
41 MODULE_LICENSE("GPL");
42 
43 #define PFX "gscps2.c: "
44 
45 /*
46  * Driver constants
47  */
48 
49 /* various constants */
50 #define ENABLE			1
51 #define DISABLE			0
52 
53 #define GSC_DINO_OFFSET		0x0800	/* offset for DINO controller versus LASI one */
54 
55 /* PS/2 IO port offsets */
56 #define GSC_ID			0x00	/* device ID offset (see: GSC_ID_XXX) */
57 #define GSC_RESET		0x00	/* reset port offset */
58 #define GSC_RCVDATA		0x04	/* receive port offset */
59 #define GSC_XMTDATA		0x04	/* transmit port offset */
60 #define GSC_CONTROL		0x08	/* see: Control register bits */
61 #define GSC_STATUS		0x0C	/* see: Status register bits */
62 
63 /* Control register bits */
64 #define GSC_CTRL_ENBL		0x01	/* enable interface */
65 #define GSC_CTRL_LPBXR		0x02	/* loopback operation */
66 #define GSC_CTRL_DIAG		0x20	/* directly control clock/data line */
67 #define GSC_CTRL_DATDIR		0x40	/* data line direct control */
68 #define GSC_CTRL_CLKDIR		0x80	/* clock line direct control */
69 
70 /* Status register bits */
71 #define GSC_STAT_RBNE		0x01	/* Receive Buffer Not Empty */
72 #define GSC_STAT_TBNE		0x02	/* Transmit Buffer Not Empty */
73 #define GSC_STAT_TERR		0x04	/* Timeout Error */
74 #define GSC_STAT_PERR		0x08	/* Parity Error */
75 #define GSC_STAT_CMPINTR	0x10	/* Composite Interrupt = irq on any port */
76 #define GSC_STAT_DATSHD		0x40	/* Data Line Shadow */
77 #define GSC_STAT_CLKSHD		0x80	/* Clock Line Shadow */
78 
79 /* IDs returned by GSC_ID port register */
80 #define GSC_ID_KEYBOARD		0	/* device ID values */
81 #define GSC_ID_MOUSE		1
82 
83 
84 static irqreturn_t gscps2_interrupt(int irq, void *dev);
85 
86 #define BUFFER_SIZE 0x0f
87 
88 /* GSC PS/2 port device struct */
89 struct gscps2port {
90 	struct list_head node;
91 	struct parisc_device *padev;
92 	struct serio *port;
93 	spinlock_t lock;
94 	char __iomem *addr;
95 	u8 act, append; /* position in buffer[] */
96 	struct {
97 		u8 data;
98 		u8 str;
99 	} buffer[BUFFER_SIZE+1];
100 	int id;
101 };
102 
103 /*
104  * Various HW level routines
105  */
106 
107 #define gscps2_readb_input(x)		readb((x)+GSC_RCVDATA)
108 #define gscps2_readb_control(x)		readb((x)+GSC_CONTROL)
109 #define gscps2_readb_status(x)		readb((x)+GSC_STATUS)
110 #define gscps2_writeb_control(x, y)	writeb((x), (y)+GSC_CONTROL)
111 
112 
113 /*
114  * wait_TBE() - wait for Transmit Buffer Empty
115  */
116 
117 static int wait_TBE(char __iomem *addr)
118 {
119 	int timeout = 25000; /* device is expected to react within 250 msec */
120 	while (gscps2_readb_status(addr) & GSC_STAT_TBNE) {
121 		if (!--timeout)
122 			return 0;	/* This should not happen */
123 		udelay(10);
124 	}
125 	return 1;
126 }
127 
128 
129 /*
130  * gscps2_flush() - flush the receive buffer
131  */
132 
133 static void gscps2_flush(struct gscps2port *ps2port)
134 {
135 	while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
136 		gscps2_readb_input(ps2port->addr);
137 	ps2port->act = ps2port->append = 0;
138 }
139 
140 /*
141  * gscps2_writeb_output() - write a byte to the port
142  *
143  * returns 1 on success, 0 on error
144  */
145 
146 static inline int gscps2_writeb_output(struct gscps2port *ps2port, u8 data)
147 {
148 	char __iomem *addr = ps2port->addr;
149 
150 	if (!wait_TBE(addr)) {
151 		printk(KERN_DEBUG PFX "timeout - could not write byte %#x\n", data);
152 		return 0;
153 	}
154 
155 	while (gscps2_readb_status(addr) & GSC_STAT_RBNE)
156 		/* wait */;
157 
158 	scoped_guard(spinlock_irqsave, &ps2port->lock)
159 		writeb(data, addr+GSC_XMTDATA);
160 
161 	/* this is ugly, but due to timing of the port it seems to be necessary. */
162 	mdelay(6);
163 
164 	/* make sure any received data is returned as fast as possible */
165 	/* this is important e.g. when we set the LEDs on the keyboard */
166 	gscps2_interrupt(0, NULL);
167 
168 	return 1;
169 }
170 
171 
172 /*
173  * gscps2_enable() - enables or disables the port
174  */
175 
176 static void gscps2_enable(struct gscps2port *ps2port, int enable)
177 {
178 	u8 data;
179 
180 	/* now enable/disable the port */
181 	scoped_guard(spinlock_irqsave, &ps2port->lock) {
182 		gscps2_flush(ps2port);
183 		data = gscps2_readb_control(ps2port->addr);
184 		if (enable)
185 			data |= GSC_CTRL_ENBL;
186 		else
187 			data &= ~GSC_CTRL_ENBL;
188 		gscps2_writeb_control(data, ps2port->addr);
189 	}
190 
191 	wait_TBE(ps2port->addr);
192 	gscps2_flush(ps2port);
193 }
194 
195 /*
196  * gscps2_reset() - resets the PS/2 port
197  */
198 
199 static void gscps2_reset(struct gscps2port *ps2port)
200 {
201 	/* reset the interface */
202 	guard(spinlock_irqsave)(&ps2port->lock);
203 	gscps2_flush(ps2port);
204 	writeb(0xff, ps2port->addr + GSC_RESET);
205 	gscps2_flush(ps2port);
206 }
207 
208 static LIST_HEAD(ps2port_list);
209 
210 static void gscps2_read_data(struct gscps2port *ps2port)
211 {
212 	u8 status;
213 
214 	do {
215 		status = gscps2_readb_status(ps2port->addr);
216 		if (!(status & GSC_STAT_RBNE))
217 			break;
218 
219 		ps2port->buffer[ps2port->append].str = status;
220 		ps2port->buffer[ps2port->append].data =
221 				gscps2_readb_input(ps2port->addr);
222 	} while (true);
223 }
224 
225 static bool gscps2_report_data(struct gscps2port *ps2port)
226 {
227 	unsigned int rxflags;
228 	u8 data, status;
229 
230 	while (ps2port->act != ps2port->append) {
231 		/*
232 		 * Did new data arrived while we read existing data ?
233 		 * If yes, exit now and let the new irq handler start
234 		 * over again.
235 		 */
236 		if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)
237 			return true;
238 
239 		status = ps2port->buffer[ps2port->act].str;
240 		data   = ps2port->buffer[ps2port->act].data;
241 
242 		ps2port->act = (ps2port->act + 1) & BUFFER_SIZE;
243 		rxflags = ((status & GSC_STAT_TERR) ? SERIO_TIMEOUT : 0 ) |
244 			  ((status & GSC_STAT_PERR) ? SERIO_PARITY  : 0 );
245 
246 		serio_interrupt(ps2port->port, data, rxflags);
247 	}
248 
249 	return false;
250 }
251 
252 /**
253  * gscps2_interrupt() - Interruption service routine
254  *
255  * This function reads received PS/2 bytes and processes them on
256  * all interfaces.
257  * The problematic part here is, that the keyboard and mouse PS/2 port
258  * share the same interrupt and it's not possible to send data if any
259  * one of them holds input data. To solve this problem we try to receive
260  * the data as fast as possible and handle the reporting to the upper layer
261  * later.
262  */
263 
264 static irqreturn_t gscps2_interrupt(int irq, void *dev)
265 {
266 	struct gscps2port *ps2port;
267 
268 	list_for_each_entry(ps2port, &ps2port_list, node) {
269 		guard(spinlock_irqsave)(&ps2port->lock);
270 
271 		gscps2_read_data(ps2port);
272 	} /* list_for_each_entry */
273 
274 	/* all data was read from the ports - now report the data to upper layer */
275 	list_for_each_entry(ps2port, &ps2port_list, node) {
276 		if (gscps2_report_data(ps2port)) {
277 			/* More data ready - break early to restart interrupt */
278 			break;
279 		}
280 	}
281 
282 	return IRQ_HANDLED;
283 }
284 
285 
286 /*
287  * gscps2_write() - send a byte out through the aux interface.
288  */
289 
290 static int gscps2_write(struct serio *port, unsigned char data)
291 {
292 	struct gscps2port *ps2port = port->port_data;
293 
294 	if (!gscps2_writeb_output(ps2port, data)) {
295 		printk(KERN_DEBUG PFX "sending byte %#x failed.\n", data);
296 		return -1;
297 	}
298 	return 0;
299 }
300 
301 /*
302  * gscps2_open() is called when a port is opened by the higher layer.
303  * It resets and enables the port.
304  */
305 
306 static int gscps2_open(struct serio *port)
307 {
308 	struct gscps2port *ps2port = port->port_data;
309 
310 	gscps2_reset(ps2port);
311 
312 	/* enable it */
313 	gscps2_enable(ps2port, ENABLE);
314 
315 	gscps2_interrupt(0, NULL);
316 
317 	return 0;
318 }
319 
320 /*
321  * gscps2_close() disables the port
322  */
323 
324 static void gscps2_close(struct serio *port)
325 {
326 	struct gscps2port *ps2port = port->port_data;
327 	gscps2_enable(ps2port, DISABLE);
328 }
329 
330 /**
331  * gscps2_probe() - Probes PS2 devices
332  * @return: success/error report
333  */
334 
335 static int __init gscps2_probe(struct parisc_device *dev)
336 {
337 	struct gscps2port *ps2port;
338 	struct serio *serio;
339 	unsigned long hpa = dev->hpa.start;
340 	int ret;
341 
342 	if (!dev->irq)
343 		return -ENODEV;
344 
345 	/* Offset for DINO PS/2. Works with LASI even */
346 	if (dev->id.sversion == 0x96)
347 		hpa += GSC_DINO_OFFSET;
348 
349 	ps2port = kzalloc(sizeof(*ps2port), GFP_KERNEL);
350 	serio = kzalloc(sizeof(*serio), GFP_KERNEL);
351 	if (!ps2port || !serio) {
352 		ret = -ENOMEM;
353 		goto fail_nomem;
354 	}
355 
356 	dev_set_drvdata(&dev->dev, ps2port);
357 
358 	ps2port->port = serio;
359 	ps2port->padev = dev;
360 	ps2port->addr = ioremap(hpa, GSC_STATUS + 4);
361 	if (!ps2port->addr) {
362 		ret = -ENOMEM;
363 		goto fail_nomem;
364 	}
365 	spin_lock_init(&ps2port->lock);
366 
367 	gscps2_reset(ps2port);
368 	ps2port->id = readb(ps2port->addr + GSC_ID) & 0x0f;
369 
370 	snprintf(serio->name, sizeof(serio->name), "gsc-ps2-%s",
371 		 (ps2port->id == GSC_ID_KEYBOARD) ? "keyboard" : "mouse");
372 	strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
373 	serio->id.type		= SERIO_8042;
374 	serio->write		= gscps2_write;
375 	serio->open		= gscps2_open;
376 	serio->close		= gscps2_close;
377 	serio->port_data	= ps2port;
378 	serio->dev.parent	= &dev->dev;
379 
380 	ret = -EBUSY;
381 	if (request_irq(dev->irq, gscps2_interrupt, IRQF_SHARED, ps2port->port->name, ps2port))
382 		goto fail_miserably;
383 
384 	if (ps2port->id != GSC_ID_KEYBOARD && ps2port->id != GSC_ID_MOUSE) {
385 		printk(KERN_WARNING PFX "Unsupported PS/2 port at 0x%08lx (id=%d) ignored\n",
386 				hpa, ps2port->id);
387 		ret = -ENODEV;
388 		goto fail;
389 	}
390 
391 #if 0
392 	if (!request_mem_region(hpa, GSC_STATUS + 4, ps2port->port.name))
393 		goto fail;
394 #endif
395 
396 	pr_info("serio: %s port at 0x%08lx irq %d @ %s\n",
397 		ps2port->port->name,
398 		hpa,
399 		ps2port->padev->irq,
400 		ps2port->port->phys);
401 
402 	serio_register_port(ps2port->port);
403 
404 	list_add_tail(&ps2port->node, &ps2port_list);
405 
406 	return 0;
407 
408 fail:
409 	free_irq(dev->irq, ps2port);
410 
411 fail_miserably:
412 	iounmap(ps2port->addr);
413 	release_mem_region(dev->hpa.start, GSC_STATUS + 4);
414 
415 fail_nomem:
416 	kfree(ps2port);
417 	kfree(serio);
418 	return ret;
419 }
420 
421 /**
422  * gscps2_remove() - Removes PS2 devices
423  * @return: success/error report
424  */
425 
426 static void __exit gscps2_remove(struct parisc_device *dev)
427 {
428 	struct gscps2port *ps2port = dev_get_drvdata(&dev->dev);
429 
430 	serio_unregister_port(ps2port->port);
431 	free_irq(dev->irq, ps2port);
432 	gscps2_flush(ps2port);
433 	list_del(&ps2port->node);
434 	iounmap(ps2port->addr);
435 #if 0
436 	release_mem_region(dev->hpa, GSC_STATUS + 4);
437 #endif
438 	dev_set_drvdata(&dev->dev, NULL);
439 	kfree(ps2port);
440 }
441 
442 
443 static const struct parisc_device_id gscps2_device_tbl[] __initconst = {
444 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00084 }, /* LASI PS/2 */
445 #ifdef DINO_TESTED
446 	{ HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00096 }, /* DINO PS/2 */
447 #endif
448 	{ 0, }	/* 0 terminated list */
449 };
450 MODULE_DEVICE_TABLE(parisc, gscps2_device_tbl);
451 
452 static struct parisc_driver parisc_ps2_driver __refdata = {
453 	.name		= "gsc_ps2",
454 	.id_table	= gscps2_device_tbl,
455 	.probe		= gscps2_probe,
456 	.remove		= __exit_p(gscps2_remove),
457 };
458 
459 static int __init gscps2_init(void)
460 {
461 	register_parisc_driver(&parisc_ps2_driver);
462 	return 0;
463 }
464 
465 static void __exit gscps2_exit(void)
466 {
467 	unregister_parisc_driver(&parisc_ps2_driver);
468 }
469 
470 
471 module_init(gscps2_init);
472 module_exit(gscps2_exit);
473 
474